The instant invention relates to circular cutting blades, and particularly to a circular cutting blade which utilizes a chain having cutter links therein serving as cutters in the blade.
Circular saw blades of the type disclosed herein are used in connection with hand-held power saws and also with brush or light timber harvesting equipment. The blade is mounted on a motor driven arbor which is rotated at relatively high speed to cause the blade to cut material, generally wood.
A number of circular saw blade assemblies utilizing chain-type cutters are known. One such blade is disclosed in U.S. Pat. No. 4,627,322 to Hayhurst, Jr., which utilizes a pair of discs which sandwich a portion of a saw chain about the periphery of the disc. Other blades utilize a circular disc having chain-saw type cutter links mounted about the periphery thereof, as by rivets or other fasteners securing the links to the disc.
Although the above-described blades are useful for their intended purposes, each blade encounters difficulties when used in extremely heavy brush or on hard materials. In the case of the first described blade, the chain portion is free to rotate about the disc, as there is no provision to engage the driving or anchor links on the saw chain. As the chain stretches during use, slippage increases as the chain is driven by the disc. In the case of units with chain-saw type cutters installed on a disc, the cutting teeth must be individually removed and replaced in the event that one of them becomes damaged, as is frequently the case when the blade is used as a brush cutter wherein it engages rocks rather than brush.
The invention of the application includes a cutting chain having links therein, including anchor links and cutter links. Each anchor link has an anchor portion which extends to one side of the chain. Opposed side links join the anchor links. Certain of the side links are cutter links. A disc having alternating sprocket teeth and gullies extending about the periphery thereof is provided The chain is secured about the periphery of the disc with the anchor portions received in the gullies. Side links in the chain straddle the sprocket teeth and serve to hold the chain from lateral displacement on the disc.
An object of the invention is to provide a cutting blade wherein anchor portions of a cutting chain are positively engaged by the disc on which the cutting chain is carried. More specifically, these anchor portions seat within gullies provided in the disc.
Another object is to provide such a cutting blade where side links in a cutting chain straddle sprocket teeth in the disc mounting the chain.
Another object of the invention is to provide a cutting blade wherein the cutting chain may be easily removed and replaced.
A further object of the invention is to provide a cutting blade wherein the cutting chain is carried on a single disc.
Yet another object of the invention is to provide a cutting blade which is easy to use, economical to manufacture and is durable.